Dtc 74-40 Short In Speaker Circuit

Body Electrical. Lexus Is250, Is220D. Gse20 Ale20
Audio Visual. Lexus Is250, Is220D. Gse20 Ale20

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

INSPECT STEREO COMPONENT AMPLIFIER

CHECK OPERATION

CHECK HARNESS AND CONNECTOR

INSPECT FRONT NO. 1 SPEAKER (LEFT HAND)

CONFIRM MODEL

INSPECT REAR NO. 2 SPEAKER (RIGHT HAND)

INSPECT REAR NO. 2 SPEAKER (LEFT HAND)

INSPECT REAR NO. 3 SPEAKER (RIGHT HAND)

INSPECT REAR NO. 3 SPEAKER (LEFT HAND)

INSPECT REAR STEREO COMPONENT SPEAKER (LEFT HAND)

INSPECT REAR STEREO COMPONENT SPEAKER (RIGHT HAND)

INSPECT FRONT STEREO COMPONENT SPEAKER

INSPECT WOOFER BOX SPEAKER

CHECK HARNESS AND CONNECTOR

INSPECT FRONT NO. 1 SPEAKER (RIGHT HAND)

INSPECT FRONT NO. 2 SPEAKER (RIGHT HAND)

INSPECT FRONT NO. 2 SPEAKER (LEFT HAND)

INSPECT FRONT NO. 3 SPEAKER (RIGHT HAND)

INSPECT FRONT NO. 3 SPEAKER (LEFT HAND)

CONFIRM MODEL

INSPECT REAR NO. 2 SPEAKER (RIGHT HAND)

INSPECT REAR NO. 2 SPEAKER (LEFT HAND)

INSPECT REAR SPEAKER (RIGHT HAND)

INSPECT REAR SPEAKER (LEFT HAND)

DTC 74-40 Short in Speaker Circuit


DESCRIPTION


DTC No.
DTC Detection Condition
Trouble Area
74-40
A short is detected in the speaker output circuit.
  1. Wire harness
  2. Speaker
  3. Stereo component amplifier
This circuit has a fail-safe function.
  1. When a short in the speaker circuit is detected, all sound outputs are stopped.

WIRING DIAGRAM


Lexus Is250, Is220D. Gse20 Ale20.Audio Visual.Audio And Visual System. Dtc 74-40 Short In Speaker Circuit


Lexus Is250, Is220D. Gse20 Ale20.Audio Visual.Audio And Visual System. Dtc 74-40 Short In Speaker Circuit


Lexus Is250, Is220D. Gse20 Ale20.Audio Visual.Audio And Visual System. Dtc 74-40 Short In Speaker Circuit


INSPECTION PROCEDURE

HINT:
After the inspection is completed, clear the DTCs.
1.INSPECT STEREO COMPONENT AMPLIFIER

  1. Disconnect the stereo component amplifier connectors P29 and P28.

  1. DTC clear and recheck.

  1. Check if DTC 74-40 is output.

    OK:
    DTC 74-40 is not output.


NG
REPLACE STEREO COMPONENT AMPLIFIER
OK


2.CHECK OPERATION

  1. Reconnect the stereo component amplifier connector P29.

  1. Check if DTC 74-40 is output.

    OK:
    DTC 74-40 is not output.


NG
Go to step 14
OK


3.CHECK HARNESS AND CONNECTOR


    Lexus Is250, Is220D. Gse20 Ale20.Audio Visual.Audio And Visual System. Dtc 74-40 Short In Speaker Circuit

  1. Disconnect the connectors shown in the illustration from the stereo component amplifier and speakers.



    Lexus Is250, Is220D. Gse20 Ale20.Audio Visual.Audio And Visual System. Dtc 74-40 Short In Speaker Circuit

  1. Measure the resistance according to the value(s) in the table below.

    Standard resistance:
    Tester connection
    		Condition
    		Specified condition
    CTR+ - Body ground (*1)
    		Always
    		10 kΩ or higher
    CTR- - Body ground (*1)
    		Always
    		10 kΩ or higher
    ML+ - Body ground (*2)
    		Always
    		10 kΩ or higher
    ML- - Body ground (*2)
    		Always
    		10 kΩ or higher
    O4-2 - Body ground (*2)
    		Always
    		10 kΩ or higher
    O4-4 - Body ground (*2)
    		Always
    		10 kΩ or higher
    MR+ - Body ground (*2)
    		Always
    		10 kΩ or higher
    MR- - Body ground (*2)
    		Always
    		10 kΩ or higher
    N4-2 - Body ground (*2)
    		Always
    		10 kΩ or higher
    N4-4 - Body ground (*2)
    		Always
    		10 kΩ or higher
    SL+ - Body ground (*1)
    		Always
    		10 kΩ or higher
    SL- - Body ground (*1)
    		Always
    		10 kΩ or higher
    SR+ - Body ground (*1)
    		Always
    		10 kΩ or higher
    SR- - Body ground (*1)
    		Always
    		10 kΩ or higher
    WFL+ - Body ground
    		Always
    		10 kΩ or higher
    WFL- - Body ground
    		Always
    		10 kΩ or higher
    WF2+ - Body ground (*2)
    		Always
    		10 kΩ or higher
    WF2- - Body ground (*2)
    		Always
    		10 kΩ or higher
    WF1+ - Body ground
    		Always
    		10 kΩ or higher
    WF1- - Body ground
    		Always
    		10 kΩ or higher
    *1: with Front Center Speaker
    *2: without Front Center Speaker


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


4.INSPECT FRONT NO. 1 SPEAKER (LEFT HAND)

  1. Resistance check.

    1. Measure the resistance between the terminals of the speaker.

      Standard resistance:
      with Front Center Speaker:
      6 to 10 Ω
      without Front Center Speaker:
      Approximately 4 Ω


NG
REPLACE FRONT NO. 1 SPEAKER (LEFT HAND)
OK


5.CONFIRM MODEL

Result:

Result
Proceed to
without Front Center Speaker
A
with Front Center Speaker
B


B
Go to step 10
A


6.INSPECT REAR NO. 2 SPEAKER (RIGHT HAND)

  1. Reconnect the stereo component amplifier connector and rear No. 2 speaker connector.

  1. Check that audio sound can be heard from the speaker.

    OK:
    Audio sound can be heard.


NG
REPLACE REAR NO. 2 SPEAKER (RIGHT HAND)
OK


7.INSPECT REAR NO. 2 SPEAKER (LEFT HAND)

  1. Reconnect the stereo component amplifier connector and rear No. 2 speaker connector.

  1. Check that audio sound can be heard from the speaker.

    OK:
    Audio sound can be heard.


NG
REPLACE REAR NO. 2 SPEAKER (LEFT HAND)
OK


8.INSPECT REAR NO. 3 SPEAKER (RIGHT HAND)

  1. Reconnect the stereo component amplifier connector and rear No. 3 speaker connector.

  1. Check that audio sound can be heard from the speaker.

    OK:
    Audio sound can be heard.


NG
REPLACE REAR NO. 3 SPEAKER (RIGHT HAND)
OK


9.INSPECT REAR NO. 3 SPEAKER (LEFT HAND)

  1. Reconnect the stereo component amplifier connector and rear No. 3 speaker connector.

  1. Check that audio sound can be heard from the speaker.

    OK:
    Audio sound can be heard.


OK
Go to step 13
NG

REPLACE REAR NO. 3 SPEAKER (LEFT HAND)

10.INSPECT REAR STEREO COMPONENT SPEAKER (LEFT HAND)

  1. Reconnect the stereo component amplifier connector and rear stereo component speaker connector.

  1. Check that audio sound can be heard from the speaker.

    OK:
    Audio sound can be heard.


NG
REPLACE REAR STEREO COMPONENT SPEAKER (LEFT HAND)
OK


11.INSPECT REAR STEREO COMPONENT SPEAKER (RIGHT HAND)

  1. Reconnect the stereo component amplifier connector and rear stereo component speaker connector.

  1. Check that audio sound can be heard from the speaker.

    OK:
    Audio sound can be heard.


NG
REPLACE REAR STEREO COMPONENT SPEAKER (RIGHT HAND)
OK


12.INSPECT FRONT STEREO COMPONENT SPEAKER

  1. Resistance check.

    1. Measure the resistance between the terminals of the speaker.

      Standard resistance:
      7 to 9 Ω


NG
REPLACE FRONT STEREO COMPONENT SPEAKER
OK


13.INSPECT WOOFER BOX SPEAKER


    Lexus Is250, Is220D. Gse20 Ale20

  1. Resistance check.

  1. Measure the resistance according to the value(s) in the table below.

    NOTICE:
    The speaker should not be removed for checking.

    Standard resistance:
    with Front Center Speaker:
    Tester connection
    		Condition
    		Specified condition
    3 - 4
    		Always
    		7 to 8.6 Ω
    without Front Center Speaker:
    Tester connection
    		Condition
    		Specified condition
    1 - 3
    		Always
    		Approximately 2 Ω
    2 - 4
    		Always
    		Approximately 2 Ω


NG
REPLACE WOOFER BOX SPEAKER
OK


14.CHECK HARNESS AND CONNECTOR


    Lexus Is250, Is220D. Gse20 Ale20.Audio Visual.Audio And Visual System. Dtc 74-40 Short In Speaker Circuit

  1. Disconnect the connectors shown in the illustration from the stereo component amplifier and speakers.



    Lexus Is250, Is220D. Gse20 Ale20.Audio Visual.Audio And Visual System. Dtc 74-40 Short In Speaker Circuit

  1. Measure the resistance according to the value(s) in the table below.

    Standard resistance:
    Tester connection
    		Condition
    		Specified condition
    FL+ - Body ground
    		Always
    		10 kΩ or higher
    FL- - Body ground
    		Always
    		10 kΩ or higher
    M4-2 - Body ground
    		Always
    		10 kΩ or higher
    M4-4 - Body ground
    		Always
    		10 kΩ or higher
    FR+ - Body ground
    		Always
    		10 kΩ or higher
    FR- - Body ground
    		Always
    		10 kΩ or higher
    L2-2 - Body ground
    		Always
    		10 kΩ or higher
    L2-4 - Body ground
    		Always
    		10 kΩ or higher
    RL+ - Body ground
    		Always
    		10 kΩ or higher
    RL- - Body ground
    		Always
    		10 kΩ or higher
    O5-2 - Body ground (*1)
    		Always
    		10 kΩ or higher
    O5-4 - Body ground (*1)
    		Always
    		10 kΩ or higher
    RR+ - Body ground
    		Always
    		10 kΩ or higher
    RR- - Body ground
    		Always
    		10 kΩ or higher
    N5-2 - Body ground (*1)
    		Always
    		10 kΩ or higher
    N5-4 - Body ground (*1)
    		Always
    		10 kΩ or higher
    WFR+ - Body ground
    		Always
    		10 kΩ or higher
    WFR- - Body ground
    		Always
    		10 kΩ or higher
    *1: with Front Center Speaker


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


15.INSPECT FRONT NO. 1 SPEAKER (RIGHT HAND)

  1. Resistance check.

    1. Measure the resistance between the terminals of the speaker.

      Standard resistance:
      with Front Center Speaker:
      6 to 10 Ω
      without Front Center Speaker:
      Approximately 4 Ω


NG
REPLACE FRONT NO. 1 SPEAKER (RIGHT HAND)
OK


16.INSPECT FRONT NO. 2 SPEAKER (RIGHT HAND)

  1. Reconnect the stereo component amplifier connector and front No. 2 speaker connector.

  1. Check that audio sound can be heard from the speaker.

    OK:
    Audio sound can be heard.


NG
REPLACE FRONT NO. 2 SPEAKER (RIGHT HAND)
OK


17.INSPECT FRONT NO. 2 SPEAKER (LEFT HAND)

  1. Reconnect the stereo component amplifier connector and front No. 2 speaker connector.

  1. Check that audio sound can be heard from the speaker.

    OK:
    Audio sound can be heard.


NG
REPLACE FRONT NO. 2 SPEAKER (LEFT HAND)
OK


18.INSPECT FRONT NO. 3 SPEAKER (RIGHT HAND)

  1. Reconnect the stereo component amplifier connector and front No. 3 speaker connector.

  1. Check that audio sound can be heard from the speaker.

    OK:
    Audio sound can be heard.


NG
REPLACE FRONT NO. 3 SPEAKER (RIGHT HAND)
OK


19.INSPECT FRONT NO. 3 SPEAKER (LEFT HAND)

  1. Reconnect the stereo component amplifier connector and front No. 3 speaker connector.

  1. Check that audio sound can be heard from the speaker.

    OK:
    Audio sound can be heard.


NG
REPLACE FRONT NO. 3 SPEAKER (LEFT HAND)
OK


20.CONFIRM MODEL

Result:

Result
Proceed to
with Front Center Speaker
A
without Front Center Speaker
B


B
Go to step 24
A


21.INSPECT REAR NO. 2 SPEAKER (RIGHT HAND)

  1. Reconnect the stereo component amplifier connector and rear No. 2 speaker connector.

  1. Check that audio sound can be heard from the speaker.

    OK:
    Audio sound can be heard.


NG
REPLACE REAR NO. 2 SPEAKER (RIGHT HAND)
OK


22.INSPECT REAR NO. 2 SPEAKER (LEFT HAND)

  1. Reconnect the stereo component amplifier connector and rear No. 2 speaker connector.

  1. Check that audio sound can be heard from the speaker.

    OK:
    Audio sound can be heard.


NG
REPLACE REAR NO. 2 SPEAKER (LEFT HAND)
OK


23.INSPECT REAR SPEAKER (RIGHT HAND)

  1. Reconnect the stereo component amplifier connector and rear speaker connector.

  1. Check that audio sound can be heard from the speaker.

    OK:
    Audio sound can be heard.


NG
REPLACE REAR SPEAKER (RIGHT HAND)
OK

REPLACE REAR SPEAKER (LEFT HAND)

24.INSPECT REAR SPEAKER (LEFT HAND)

  1. Resistance check.

    1. Measure the resistance between the terminals of the speaker.

      Standard resistance:
      Approximately 4 Ω


NG
REPLACE REAR SPEAKER (LEFT HAND)
OK

REPLACE REAR SPEAKER (RIGHT HAND)